Flexible street script/tool?
Using curves you should be able to do something similar.



On top view add a curve, give it some extrusion and depth. Enter edit mode and align the control points by pressing SY0.
Exit edit mode and rotate the curve 90 degrees on the x axis (RX90) Go back to edit mode and manipulate your curve by adding points (Ctrl RMB and manipulating them you can get any shape you want.